Piston-pin bearing lubrication system and method for a two sroke internal combustion engine

ABSTRACT

An improved lubrication system and method for the normally contacting and abutting piston pin and connecting rod journal bearing surfaces of an internal combustion engine that includes an inertia pump in a connecting rod. The inertia pump reacts to the movement of the connecting rod and conveys a predetermined measure of lubricating oil at a high enough pressure to overcome the forces which cause the surfaces to normally maintain contact. By separating the normally contacting surfaces of the pin and the connecting rod journal, the surfaces become lubricated. Several embodiments of inertia pumps provide variations in implementing the invention.

RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application Ser.No. 60/832,646 filed Jul. 21, 2006.

TECHNICAL FIELD

This invention is related to the field of internal combustion enginesand more specifically to a lubrication system and method that supplieslubricating oil to the piston-pin bearings of two-cycle engines.

BACKGROUND

Some conventional internal combustion engines are configured to providelubricating oil to piston-pin bearings by pumping the oil into the smallgap surrounding much of the circumference of the pin. However because ofthe way two-cycle engines operate, one portion of the pin is in constantcontact with the journal surface of the connecting rod during the entirestroke cycle of the engine. That portion is difficult to lubricate andis subject to wear.

In some two-cycle engines, such as the Internal Combustion Engine With ASingle Crankshaft And Having Opposing Cylinders And Opposing Pistons InEach Cylinder (“OPOC engine”) described in my U.S. Pat. No. 6,170,443and incorporated herein by reference, lubricating oil is pumped throughpassages in the crankshaft and connecting rods to the piston pins.

There is a need to improve the piston-pin lubrication system as itapplies to two-cycle engines, since available oil pressure inconventional engines does not overcome the combustion gas forces andinertia forces that act on the piston-pins during the entire strokecycle in the direction towards the crankshaft to provide effectivelubrication. Without sufficient lubrication, excess heat and frictionalwear may result.

SUMMARY

The present invention provides several improvements to the piston-pinlubricating system of two-cycle engines. Several embodiments are shownwhich utilize an inertia pump in a connecting rod to overcome the forcesand inject the proper amount of oil between the normally abuttingbearing surfaces of the piston-pin and connecting rod journal.

The use of inertia pumps in the embodiments takes advantage of thechanging speeds of the pistons and connecting rods that occur duringeach stroke cycle of the engine. The acceleration and decelerationforces cause the plunger mass within each the inertia pump to react andcause the pump to become charged with lubricating oil as it approachesits top dead center (“TDC”) position and then to inject a predeterminedamount of oil under high pressure between the surfaces of the piston pinand the connecting rod journal as it approaches bottom dead center(“BDC”) position. The timing of the injection near BDC is selectedbecause the gas forces present on the piston are at their minimum andonly the inertia forces on the piston have to be overcome by the outputof the inertia pump. This causes a sufficient separation between thesurfaces to allow a predetermined charge of lubricating oil to flowthere-between.

In a first embodiment of an inertia pump, a single check valve isemployed along with an inertia driven plunger. The check valve becomesopen and allows oil to flow from an external pressure source (the engineoil pump) into the pumping chamber and out of the inertia pump into thepiston pin bearing during the time when the piston decelerates whileapproaching its TDC in the later part of the compression stroke and alsowhen the piston accelerates during the early portion of the expansionstroke following TDC.

As the piston passes through its mid-compression stroke andmid-expansion stroke the inertia forces become minimal and the angles ofthe connecting rods with respect to the piston pins are at theirextremes. During these strokes the check valve opens and oil from theexternal pressure source flows through the inertia pump and into groovesformed in the piston pin and journal.

In reaction to the inertia caused movement of the pump plunger mass andthe check valve mass as the piston decelerates during the later portionof the expansion stroke as it approaches BDC and during the accelerationthat occurs during the early portion of the compression strokeimmediately following BDC, the check valve closes and the pump plungerforces oil out of the inertia pump under high pressure. The closed checkvalve prevents the oil pumped by the pump plunger from flowing back tothe pressure source while the inertia pump forces oil into the pistonpin bearing under a high pressure that is greater than the inertiapressure holding the bearing surfaces together. This results in a briefseparation of the surfaces and their lubrication.

In a second embodiment, the check valve is replaced with a freelysliding inertia mass valve that moves independent of the inertia drivenpump plunger. In this embodiment, the operation is similar to the firstembodiment. However, the inertia valve is subject to the inertia inducedmotion in the valve chamber independent of the same inertia forces thatsubject the pump plunger to move within the pump chamber. By beingindependently subject to the same inertia forces that are applied to theplunger, the inertia valve can be selected to react earlier or laterthan the plunger during the stroke cycle to prolong or earlier terminatethe flow of oil from the source through the inertia pump. One result ofearlier termination would be for the plunger to inject more oil into thespace forced open between the bearing surfaces.

It is an object of the present invention to provide an improvedlubricating system and method for a two-cycle engine by providing aninertia pump within a connecting rod to supplement the flow oflubricating oil into the associated piston pin by forcibly injecting apredetermined amount of oil between the abutting piston pin and theconnecting rod journal surfaces.

It is another object of the present invention to provide an improvedlubricating system and method for a two-cycle engine by providing an oilpump that acts in response to deceleration and acceleration of thepiston as it approaches and exits its BDC portion of the stroke toovercome the forces between the abutting piston pin and the connectingrod journal surfaces and injecting a predetermined amount of oiltherebetween.

It is a further object of the present invention to provide improvedinertia pumps suitable for use within the moving components of aninternal combustion engine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cutaway drawing of a two-cycle OPOC engine showing thelocation of the embodiments of the present invention.

FIG. 2A is a cross-sectional view of a first embodiment of an inertiapump used in the inner piston connecting rods the OPOC engine shown inFIG. 1.

FIG. 2B is a cross-sectional view of the piston plunger of the inertiapump shown in FIG. 2A taken along section lines 2B-2B.

FIG. 2C is a cross-sectional view of a first embodiment of an inertiapump used in the outer piston connecting rods the OPOC engine shown inFIG. 1.

FIG. 2D is a cross-sectional view of the piston plunger of the inertiapump shown in FIG. 2C taken along section lines 2D-2D.

FIG. 3A is a cross-sectional view of a second embodiment of an inertiapump used in the connecting rods the OPOC engine shown in FIG. 1 nearand at TDC of the stroke cycle.

FIG. 3B is a cross-sectional view of the inertia pump shown in FIG. 3Aat the mid-stroke position between TDC and BDC.

FIG. 3C is a cross-sectional view of the inertia pump shown in FIGS. 3Aand 3B near and at BDC of the stroke cycle.

FIG. 3D is a cross-sectional view of the pumping chamber taken alonglines 3D-3D in FIG. 3A.

FIG. 4A is a cross-sectional view of a third embodiment of an inertiapump used in the connecting rods the OPOC engine shown in FIG. 1 nearand at TDC of the stroke cycle.

FIG. 4B is a cross-sectional view of the inertia pump shown in FIG. 4Aat the mid-stroke position between TDC and BDC.

FIG. 4C is a cross-sectional view of the inertia pump shown in FIGS. 4Aand 4B near and at BDC of the stroke cycle.

FIG. 4D is a cross-sectional view of the pumping chamber taken alonglines 4D-4D in FIG. 4A.

FIG. 5A is a cross-sectional view taken across the axis of a piston-pinwithin a piston journal when the piston is at its BDC position.

FIG. 5B is a cross-sectional view taken across the axis of thepiston-pin shown in FIG. 5A rotated to one extreme during the strokecycle.

FIG. 5C is a cross-sectional view taken across the axis of thepiston-pin shown in FIG. 5A rotated to its opposite extreme during thestroke cycle.

FIG. 6 is a perspective view of an inner piston connecting rod of anOPOC engine such as shown in FIG. 1.

FIG. 7 is a perspective view of the underside of an inner piston andassociated piston pin of an OPOC engine such as shown in FIG. 1accommodated for use with the present invention.

FIG. 8 is a perspective view of the present invention installed withinthe outer connecting rods of an OPOC engine such as shown in FIG. 1.

FIG. 9 is a chart that shows the plot the inertia forces present on aninertia pump plunger during a full stroke cycle of the inner and outerpistons in an OPOC engine, such as shown in FIG. 1.

DETAILED DESCRIPTION OF EXEMPLIFIED EMBODIMENTS

While the present invention is summarized above as being applicable forseveral types of internal combustion engines, it is exemplified hereinas being installed in a two-cycle OPOC engine, such as that shown in myreferenced patent.

In FIG. 1, opposing left cylinder 102 and right cylinder 104 of an OPOCengine 100 are shown in a cut-away view. Inner pistons PLI (left) andPRI (right) respectively oppose outer piston PLO (left) and PRO (right)within the corresponding cylinders 102 and 104. Inner connecting (push)rods 120 and 130 provide power connections between the inner pistons PLIand PRI and the crankshaft 110. Outer connecting (pull) rod sets 140,141 and 150, 151 provide power connections between the outer pistons PLOand PRO and crankshaft 110. Each of the connecting rods has a “small”end which is connected to a piston pin. Piston pins 180 and 190 areassociated with pistons PLI and PRI, while piston pins 142 and 143 areassociated with pistons PLO and PRO. In FIG. 6 a detailed view of pushrod 120 is shown, while in FIG. 8 a detailed view of pull rods 140 and141 are shown.

In each connecting rod, an inertia pump is shown as installed to providethe lubrication to the piston pin as discussed above in the Summary ofthe Invention. Inertia pumps 200, 201, 300, 300′, 200′ and 201′ arerespectively installed in corresponding connecting rods 140, 141, 120,130, 150 and 151. Each connecting rod has oil passages that function ina conventional way to convey lubricating oil from an oil pump throughthe crankshaft and connecting rods to the piston pins. However, byadding inertia pumps within the passages, it is possible to achieve theobjects of the present invention.

In FIGS. 2A and 2B, a first embodiment of an inertia pump 200, such asthat shown installed in pull rod 140 in FIG. 1, is shown. Pump 200 has ahousing 201 and is shown for use in association with a pull rod andouter left piston PLO. A plunger 202 is the core of the pump since itslides within a two stage bore in the pump housing 201 in reaction todeceleration and acceleration forces present in the pull rod over thestroke cycle. The plunger 202 is defined to have a first cylindricalmass portion 204 with grooves 203 formed along its length. The grooves203 are sufficiently large to allow the plunger to be moved by inertiaforces with little resistance by oil present in the housing and also toallow oil to pass through the pump from the entry port 206 to the outletport 216 due to pressure maintained by the engine oil pump (not shown).

The two stage pump bore includes an oil supply section 205 and a plungerbore section 207. The plunger element 202 is also a two stage elementthat resides within the pump bore and its plunger mass portion 204resides totally in bore section 213 and its plunger pump portion 210extends from plunger mass portion 204 to move within plunger boresection 207. A stopper element 209 is located at one end of section 205to limit movement of the plunger element therein. Stopper element 209 isadjacent an input port 206 through which oil enters inertia pump 200from the lubricating passages in the connecting rod.

The embodiment of the inertia pump 200 shown in FIGS. 2A and 2B isexemplified as being in the final portion of its stroke towards BDC, atBDC, or in the early portion of the stroke following BDC. At thisposition the inertia forces continue to push the plunger element to itsextreme left position, as the outer left piston PLO would be at BDC, andthe oil has been expelled at a high pressure from the bore section 207by the plunger pump portion 210. (See the plot of forces approaching andleaving 0 (360) degrees or BDC position in FIG. 9.)

A normally open check valve 212 is provided in the pump chamber 214. Inthe shown position, the pressure provided by the inertia pump and theinertia forces acting on the valve itself cause check valve 212 toclose. This closing serves to concentrate the oil being pumped by theplunger pump portion 210 into outlet port 216 and into the piston pinbearing. When closed, check valve 212 also prevents back-flow into theoil supply passages in the connecting rod.

In other positions of the stroke, check valve 212 remains open andallows lubricating oil from the engine oil pump to provide oil in aconventional manner through the connecting rod and inertia pump 200 viainput port 206, grooves 203, passage 208, check valve 212, chamber 214and outlet port 216. Although such pressure is sufficient to effectlubrication of parts of the piston pin and journal surfaces, it is notsufficient to overcome the forces which cause the portions of the pinand piston journal surfaces to be held together.

In FIGS. 2C and 2D, an embodiment off an inertia pump 300 is shown to besuitable for installation in a push rod, such as 120 associated withleft inner piston PLI. In that embodiment, the pump 300 has a housing301 with an inlet port 306 and an outlet port 316. The pump embodimentshown in FIG. 2C is oriented opposite to the embodiment shown in FIG.2A, since the inertia forces acting on those pumps approaching andleaving the BDC positions of their associated outer and inner pistonsare opposite.

In FIG. 2C, a plunger 302 is also the core of the pump since it slideswithin a two stage bore in pump housing 301 in reaction to decelerationand acceleration forces present in the push rod over the stroke cycle.The plunger 302 is defined to have a first cylindrical mass portion 304with grooves 303 formed along its length. The grooves 303 aresufficiently large to allow the plunger to be moved by inertia forceswith little resistance by oil present in the housing and also to allowoil to pass through the pump from the entry port 206 to the outlet port216 due to pressure maintained by the engine oil pump (not shown). Thegrooves 303 also provide a path for oil to flow under high pressure whenit is pumped by plunger element 302.

The two stage pump bore includes a mass bore section 305 and a plungerbore section 207. Mass bore section 305 is also in communication withthe outlet port 316. The plunger element 302 is also a two stage elementthat resides within the pump bore and its plunger mass portion 304resides totally in mass bore section 305 and its plunger pump portion310 extends from plunger mass portion 304 to move within plunger boresection 307. A stopper element 309 is located at one end of section 305to limit movement of the plunger element therein. Stopper element 309 isadjacent a central outlet port opening 316 through which oil exits theinertia pump 300 to the piston pin bearing.

A normally open check valve 312 is provided in the pump chamber 314. Inthe shown position, the pressure provided by the inertia pump and theinertia forces acting on the valve itself cause check valve 312 toclose. This closing serves to concentrate the oil being pumped by theplunger pump portion 310 through passage 308, plunger grooves 303,outlet port 216 and into the piston pin bearing. When closed, checkvalve 212 also prevents back flow into the oil supply passages in theconnecting rod.

In positions other than approaching and leaving BDC, the check valve 312opens and allows lubrication oil from the lower pressure oil pump systemto flow in a conventional manner through the inertia pump and into thebearing as discussed above.

FIGS. 4A-4D illustrate yet another embodiment of an inertia pump 600that can be utilized in the present invention. In this embodiment, theFigures illustrate the same inertia pump 600 in three different stagesof its operation. In FIG. 4A, the associated piston is in the later partof its compression stroke approaching TDC, at TDC or beginning itsexpansion stroke following TDC. In this position, oil from thelubrication system pump is allowed to flow through inertia pump 600 andto the associated piston pin. Housing 601 has an oil entry port 606 andan outlet port 616. A two stage plunger element 602 has a plunger massportion 604 and a pump plunger portion 610 that is similar to the otherembodiments discussed above. As in the prior embodiment, the plungermass portion 604 contains at least one aperture or groove 603 thatallows oil to freely flow from entry port 606 and into a pump bore 611and reduces and resistance to the longitudinal movement of the plungermass within pump bore 611.

A pump chamber 614 surrounds pump plunger 610 and contains a set ofgrooved openings 618 that allow oil to flow past pump plunger 610 whenit is in the position shown in FIG. 4A.

A cylindrical mass 612 containing a central passage 619 freely moveswithin a bore 615 and replaces check valve 512 shown in the priordescribed embodiment. Cylindrical mass 612 is neither normally open nornormally closed, as spring loaded check valves are configured. Instead,cylindrical mass 612 is inertia driven, but independent from the plunger602. In this configuration, cylindrical mass 612 can be configured byits size, its mass and its aperture resistance to open and close thesupply opening 617 at precise positions in the stoke cycle and therebyprovide for increased timing of the oil flow from the conventionalengine pump source while allowing the pump chamber 614 to become primedwhen plunger 610 is driven as it approaches BDC.

In FIG. 4A, supply opening 617 is open because inertia forces havecaused cylindrical mass 612 to be located at the right side of bore 617.Oil from the conventional source, is pumped through inertia pump 600 viaentry port 606, plunger aperture 603, chamber 611, grooves 618, intobore 621, and oil passage 613, port 617 aperture 619, chamber 614,passage 615 and outlet port 616.

Passage 613 is indicated as ghost lines in FIGS. 4A, 4B and 4C. Passage613 is better illustrated in FIG. 4D as being offset from the planarsection provided for FIGS. 4A, 4B and 4C. Passage 613 providescommunication flow of lubricating oil between plunger chamber 611 andpump chamber 614. In the position illustrated in FIG. 4A, thelubricating oil sourced under normal pressure from the engine oil pumppasses through pump chamber 614, leaving it filled and primed, and intopassage 615 to exit through outlet port 616.

In FIG. 4B, the inertia pump is shown at a later portion of theexpansion stroke when inertia forces are starting to reverse and therebycausing the cylindrical mass 612 to be forced towards the left andclosing port 617. Independently, plunger mass 602 is also forced towardsthe left and grooves 618 become blocked. With port 617 being closed bycylindrical ass 612 and grooves 618 blocked by plunger mass 602 beingforced towards the left, high pressure is being developed by themovement of plunger pump 610 in bore 621. This prevents conventionallypumped lubricating oil from flowing into the bearing while pressure isbuilt up to overcome the forces which cause the bearing surfaces to beforced together.

In FIG. 4C, pump 600 is shown as having reached the later portion of theexpansion stroke approaching BDC, at BDC, or in the beginning of thecompression stroke following BDC. In these positions, the inertia forcespresent in pump 600 become high enough to cause the injection of apredetermined volume of lubrication oil between the piston pin andpiston journal surfaces. Forces present at the output port 616 cause thepiston pin and piston journal surfaces to be separated sufficiently toallow oil to flow therebetween.

With reference to FIGS. 5A, 5B, 5C, 6 and 7, the piston pin andconnecting rod journal lubrication distribution system for a piston isshown. In the figures, piston pin 180 is mounted on an inner piston PLIand has a central surface which fit within a journal 188 at the smallend of an inner piston connecting rod 120. In these drawings, theinertia pumps have not been indicated. However, the ghost lines of FIG.6 indicate oil passages and a void were an inertia pump is located. Theconnecting rod 120 is constantly being driven by either its associatedinner piston or the crankshaft and its small end is subject tooscillatory movement over the limited angles indicated beyond TDC andBDC.

FIG. 5A illustrates the orientation of a piston pin at both its TDC andBDC positions. An axial oil passage 182 is formed in piston pin 180 andis in communication a radial passage 184. An arcing groove 186 is formedon the outer surface of the piston pin 180 and is aligned with theopening of radial passage 184. In the small end 122 of connecting rod120 (FIG. 6), a journal is formed having a cylindrical surface 188 thatis slightly larger in diameter than the piston pin 180. Spaced apartcross grooves 187 and 189 are formed in the journal surface. Oil passage124, in communication with the outlet port of an inertial pump withinthe connecting rod, opens through the journal surface 188 and is inconstant registration and alignment with arcing groove 186 in piston pin10.

In operation in conjunction with the inertia pump, oil flows from theinertia pump when the piston is at BDC in FIG. 5A. The oil is injectedat a high enough pressure to overcome the inertia pressures forcing thesurfaces 185 and 188 together. The oil flows from passage 124 into arcgroove 186 and spreads over the adjacent area of the abutting surfacesto provide lubrication.

When the engine cycles past BDC and the connecting rod approaches theextreme limit of its angle in a first direction, cross groove 187becomes exposed to arc groove 186 and oil from the conventionallubrication pump flows into the cross groove. Lubricating oil is thenspread over that portion of the abutting surfaces 188 and 185 that passover cross groove 187.

Likewise, when the engine cycles past TDC and the connecting rodapproaches the extreme limit of its angle in a second direction, crossgroove 189 becomes exposed to arc groove 186 and oil from theconventional lubrication pump flows into cross groove 189. Lubricatingoil is then spread over that portion of the abutting surfaces 188 and185 that pass over cross groove 189.

In FIG. 8, an outer piston pin and connecting rod assembly is shownwherein connecting rods 140 and 141 each contain inertia pumps 200 and201. Connecting rods 140 and 141 are connected to a cross member 145which supports an outer piston pin 142. In this case, the outer pistonpin contains a pair of arc grooves 146 and 146′. Oil passages 144 and144′ are centrally located within each arc groove to provide theinjected oil from the inertia pump and oil from a conventional oil pumpidentical in manner to that explained with respect to the inner pistonpins above. That is, the journal of the outer piston (not shown) hasspaced apart cross grooves to distribute oil when the inertia pump isnot injecting lubricating oil between the abutting bearing surfaces.

From the foregoing, it can be seen that there has been brought to theart a new and improved system and method for lubricating the normallycontacting surfaces of a piston pin and connecting rod journal in aninternal combustion engine. It is to be understood that the precedingdescription of the embodiments is merely illustrative of some of themany specific embodiments that represent applications of the principlesof the present invention. Clearly, numerous and other arrangements wouldbe evident to those skilled in the art without departing from the scopeof the invention as defined by the following claims.

1. A system for lubricating normally abutting bearing surfaces between apiston pin and the small end journal of a connecting rod of an internalcombustion engine in which said piston pin and said small end journaltogether provide a rotatable connection between a piston and itscorresponding connecting rod, comprising: a source of lubricating oilbeing pumped under a first level of pressure; communicating passagesformed in the crankshaft and connecting rods of said engine fordelivering lubricating oil from said source to said abutting bearingsurfaces; a pump installed within a connecting rod in communication withsaid passages to receive said lubricating oil from said source; whereinsaid pump provides a predetermined measure of lubricating oil betweensaid abutting surfaces as said piston reaches bottom dead center portionof its stroke cycle.
 2. A system as in claim 1, wherein said pump reactsto the movement of the connecting rod in which it is installed toprovide said predetermined measure of lubricating oil between saidnormally abutting surfaces as said piston reaches bottom dead centerportion of its stroke cycle.
 3. A system as in claim 2, wherein saidpump contains elements which are movable in directions parallel to thelongitudinal inertia forces created in said connecting rod during thestroke cycle.
 4. A system as in claim 3, wherein said pump containsvalving elements which remain open to allow oil to flow from said sourceand through said pump to said normally abutting surfaces at a firstpressure level that is a function of the source pressure and theresistance presented by said passages and the valves over other portionsof the stroke cycle.
 5. A system as in claim 4, wherein said pumpvalving elements are closed when deceleration forces reach apredetermined level as said piston reaches the bottom dead centerportion in the stroke cycle and said movable elements force saidpredetermined measure of oil to be injected between said abuttingsurfaces at a second pressure level that is higher than said firstpressure level.
 6. A system as in claim 5, wherein said second pressurelevel is sufficient to cause temporary separation between said normallyabutting surfaces and to allow lubricating oil to be distributedtherebetween.
 7. A system as in claim 2, wherein said pump contains anunbiased reciprocating plunger element within a bore that is orientedwithin said connecting rod to allow movement of said plunger along itslongitudinal axis within said bore and such movement is an inertiareaction to acceleration and deceleration forces generated by thereciprocating movement of the piston during its stroke cycle andcommunicated into said connecting rod.
 8. A system as in claim 7,wherein said pump further contains valving elements which remain open toallow oil to flow from said source and through said pump to saidnormally abutting surfaces over other portions of the stroke cycle at afirst pressure level that is a function of the source pressure and theresistance presented by said passages and the valves.
 9. A system as inclaim 8, wherein said plunger element serves as a valving element overother portions of said stroke cycle.
 10. A system as in claim 9, whereinsaid plunger element is a two stage mass, including a first stageportion that slides within a first portion of said bore and containsseveral longitudinally formed passages to allow oil to flow therethoughwhen said plunger element moves within said bore; and a second stageportion that slides within a second portion of said bore to provide theinjection of a predetermined measure of lubricating oil from said secondportion of said bore out of said pump and between said normally abuttingsurfaces.
 11. A method of lubricating normally contacting surfaces of apiston pin and the small end journal of a connecting rod of an internalcombustion engine in which said piston pin and said small end journaltogether provide a connection between a piston and its correspondingconnecting rod, comprising the steps of: providing a source oflubricating oil at a first level of pressure; providing the crankshaftand connecting rods of said engine with communicating passages for thedelivery of lubricating oil from said source to said normally contactingsurfaces; providing a pump within a connecting rod to be incommunication with said communicating passages to receive saidlubricating oil from said source; and injecting a predetermined measureof lubricating oil between said normally contacting surfaces as saidpiston reaches bottom dead center portion of its stroke cycle.
 12. Themethod of claim 10, wherein said pump is provided to react to themovement of its associated connecting rod to provide said predeterminedmeasure of lubricating oil between said normally contacting surfaces assaid piston reaches bottom dead center portion of its stroke cycle. 13.The method of claim 12, wherein said pump is provided to containelements which are movable in directions parallel to the longitudinalinertia forces created in said connecting rod during the stroke cycle.14. The method of claim 13, wherein said pump is provided to containvalving elements which remain open to allow oil to flow from said sourceand through said pump to said normally contacting surfaces at a firstpressure level over other portions of the stroke cycle; and said firstpressure level being a function of the source pressure and theresistance presented by said passages and valving elements.
 15. Themethod of claim 14, wherein said pump valving elements are closed whendeceleration forces reach a predetermined level as said piston reachesthe bottom dead center portion in the stroke cycle and said movableelements inject said predetermined measure of oil between saidcontacting surfaces at a second pressure level that is higher than saidfirst pressure level.
 16. The method of claim 15, wherein said secondpressure level is sufficient to cause temporary separation between saidnormally contacting surfaces and to allow lubricating oil to bedistributed therebetween.
 17. The method of claim 12, wherein said pumpis provided to contain an unbiased reciprocating plunger element withina bore that is oriented within said connecting rod to allow movement ofsaid plunger along its longitudinal axis within said bore and suchmovement is an inertia reaction to acceleration and deceleration forcesgenerated by the reciprocating movement of the piston during its strokecycle and communicated into said connecting rod.
 18. The method of claim17, wherein said pump is provided to contain valving elements whichremain open to allow oil to flow from said source and through said pumpto said normally contacting surfaces at a first pressure level that isdetermined by the source pressure and the resistance presented by saidpassages and valving elements over other portions of the stroke cycle.19. The method of claim 18, wherein said plunger element is provided toserve as a valving element over other portions of said stroke cycle. 20.The method of claim 19, wherein said plunger element is provided as atwo stage mass, including a first stage portion that slides within afirst portion of said bore and contains several longitudinally formedpassages to allow oil to flow therethough when said plunger elementmoves within said bore; and a second stage portion that slides within asecond portion of said bore to provide the injection of a predeterminedmeasure of lubricating oil from said second portion of said bore out ofsaid pump and between said normally contacting surfaces.